The background is to show the ColorScale in all the views contained in a Viewer.
If the option ffpEnabe is set as false, The ColorScale just display an RED inteval.
Handle(OpenGl_GraphicDriver)::DownCast(myGraphicDriver)->ChangeOptions().ffpEnable = Standard_False;

If ffpEnable is true and there is multiple views in a vierer, the ColorScale display in views has serious issue, please see the picture for details.

Could you please check consistency in computation code of Draw Harness and AIS_ColorScale taking into account this type change? For instance, aPos in Draw is still vector of reals, and converted into integers.

Now 'vcolorscale' command works correctly with the active view. Changed types of some variables from Standard_Real to Standard_Integer. Added options to set the width or the height of color scale explicitly. Test case is added.

Now 'vcolorscale' command works correctly with the active view. Changed types of some variables from Standard_Real to Standard_Integer. Added options to set the width or the height of color scale explicitly. Test case is added.